Chronic kidney disease is associated with increased risk of sudden cardiac death among patients with coronary artery disease. Kidney Int. 2009;76:652-658. [PMID: 19536082 DOI: 10.1038/ki.2009.219]

Implantable Cardioverter Defibrillators in Prevention of Sudden Cardiac Death in Kidney Transplant Recipients: A Case Series and an Appraisal of Current Evidence

Background: Cardiovascular diseases, including sudden cardiac death (SCD), are the leading cause of mortality among kidney transplant recipients (KTRs). While implantable cardioverter defibrillators (ICDs) are established for SCD prevention in the general population, data on the benefits in patients with CKD is scarce and controversial, and there is no established general consensus on their use in this group of patients. Furthermore, data for KTRs are lacking. The aim of this study is to present our experience with ICDs in KTRs and evaluate the outcomes in this population. Methods: We retrospectively analyzed medical records of KTRs who received a kidney allograft between October 1973 and December 2023 and received ICDs for the prevention of SCD. Results: Of 2282 KTRs, 10 patients (0.44%) underwent an ICD implantation with an average age of 60.6 years at the time of implantation; 9 were male. Primary prevention of SCD was the most common indication, with only one patient receiving an ICD following sudden cardiac arrest. The female patient received an ICD while on dialysis, and the rest of the patients received ICDs in the posttransplant period with an average time of 9.1 years after KT. Kidney allograft function was reduced in all patients at the time of the ICD implantation with an average estimated glomerular filtration rate (eGFR) of 44 mL/min/1.73 m2. No ICD-related complications were recorded. Six patients are alive with an average follow-up of 5.2 years. Conclusions: ICD implantation in carefully selected KTRs may offer survival benefits and can be a valuable tool in preventing SCD. Larger studies are needed to confirm these findings and establish clear guidelines for ICD use in this specific population.

Association between glycated albumin and sudden death in patients undergoing hemodialysis

BACKGROUND

The frequency of sudden death and its risk factors in patients undergoing hemodialysis are unknown. This study was performed to examine the association between glycated albumin (GA) and sudden death in Japanese patients undergoing hemodialysis.

METHODS

In total, 260 patients undergoing hemodialysis aged ≥18 years were retrospectively followed for a mean of 4.6 years. The patients' serum GA levels were divided into tertiles, and the patients' sex, age, albumin level, C-reactive protein (CRP) level, and cardiothoracic ratio (CTR) were selected as adjustment factors. A logistic regression model was used to calculate the odds ratio (OR) for the occurrence of sudden death by GA level.

RESULTS

Ninety-one patients died during follow-up. Of the 91 deaths, 23 (25.2%) were defined as sudden deaths. Compared with non-sudden death cases, sudden death cases were significantly younger (p = 0.002) and had a higher proportion of men (p = 0.03), a higher proportion of diabetes (p = 0.008), and higher GA levels (p = 0.023). Compared with patients with the lowest GA levels (<15.2%), those with the highest GA levels (≥18.5%) had a sex- and age-adjusted OR for sudden death of 5.40 [95% confidence interval (CI): 1.35-21.85]. After adjusting for the albumin level, CRP level, and CTR in addition to sex and age, the OR for sudden death of patients with the highest GA levels increased to 6.80 (95%CI: 1.64-28.08); the relationship did not change.

CONCLUSION

Serum GA levels were significantly associated with sudden death in patients undergoing hemodialysis.

Association of Diabetes with Changes in Blood Pressure during Hemodialysis: A Secondary Analysis of the Frequent Hemodialysis Network Daily Trial

INTRODUCTION

Diabetes mellitus is a common cause of kidney failure and is often complicated by autonomic neuropathy, which may have implications for blood pressure (BP) homeostasis during hemodialysis (HD).

METHODS

In this post hoc analysis of the Frequent Hemodialysis Network (FHN) Daily Trial, we used random effects Poisson and linear regression models to estimate the association of diabetes (vs. not) with intra-dialytic hypotension (IDH) and peri-dialytic BP parameters, respectively. We tested for differential associations according to the randomized treatment (6/week vs. 3/week HD) and pre-HD systolic BP.

RESULTS

Of the 244 patients with intra-dialytic BP data, 100 (41%) had diabetes at baseline. The mean age was 51 ± 14 years; overall, 39% were female. In adjusted models, diabetes (vs. not) was associated with a 93% higher risk of developing IDH (IRR: 1.93; 95% CI: 1.26, 2.95). There was no evidence that the randomized treatment assignment modified the association between diabetes and IDH (pinteraction = 0.32), but more potent associations were noted among those with higher pre-HD systolic BP (pinteraction < 0.001). Diabetes (vs. not) was associated with a lower adjusted nadir intra-HD BP (-4.2; 95% CI: -8.3, -0.2 mm Hg) but not with the pre- or post-HD systolic BP.

CONCLUSIONS

Among participants of the FHN Daily Trial, patients with diabetes had a higher risk of IDH and lower nadir intra-HD systolic BP than patients without diabetes, even when undergoing HD up to 6 times per week.

New Insights on Cardiac Arrhythmias in Patients With Kidney Disease

The risk of arrhythmia and its management become increasingly complex as kidney disease progresses. This presents a multifaceted clinical challenge. Our discussion addresses these specific challenges relevant to patients as their kidney disease advances. We highlight numerous opportunities for enhancing the current standard of care within this realm. Additionally, this review delves into research concerning early detection, prevention, diagnosis, and treatment of various arrhythmias spanning the spectrum of kidney disease.

Do Implantable Cardioverter-Defibrillators Prevent Sudden Cardiac Death in End-Stage Renal Disease Patients on Dialysis?

Chronic kidney disease patients appear to be predisposed to heart rhythm disorders, including atrial fibrillation/atrial flutter, ventricular arrhythmias, and supraventricular tachycardias, which increase the risk of sudden cardiac death. The pathophysiological factors underlying arrhythmia and sudden cardiac death in patients with end-stage renal disease are unique and include timing and frequency of dialysis and dialysate composition, vulnerable myocardium, and acute proarrhythmic factors triggering asystole. The high incidence of sudden cardiac deaths suggests that this population could benefit from implantable cardioverter-defibrillator therapy. The introduction of implantable cardioverter-defibrillators significantly decreased the rate of all-cause mortality; however, the benefits of this therapy among patients with chronic kidney disease remain controversial since the studies provide conflicting results. Electrolyte imbalances in haemodialysis patients may result in ineffective shock therapy or the appearance of non-shockable underlying arrhythmic sudden cardiac death. Moreover, the implantation of such devices is associated with a risk of infections and central venous stenosis. Therefore, in the population of patients with heart failure and severe renal impairment, periprocedural risk and life expectancy must be considered when deciding on potential device implantation. Harmonised management of rhythm disorders and renal disease can potentially minimise risks and improve patients' outcomes and prognosis.

Incidence and Predictors of Cardiac Arrest Among Patients Admitted to the Intensive Care Units of a Comprehensive Specialized Hospital in Central Ethiopia

Background

Cardiac arrest (CA) is a common public health problem. Worldwide, cardiac arrest ranks highly among hospitalised patients' public health concerns, particularly in low-income nations. Data on cardiac arrest in intensive care units in low-income countries are relatively scarce. Determining the incidence and predictors of cardiac arrest among ICU patients will be a very crucial and fruitful clinical practice in resource-limited areas like Ethiopia.

Methods

A retrospective cohort study was conducted by reviewing charts of 422 systematically selected patients admitted to the ICU from 2018 to 2022 in Wachemo University Comprehensive Specialized Hospital. The extraction tool was used for the data collection, Epi-data version 4.6.0 for data entry, and STATA version 14 for data cleaning and analysis. Kaplan-Meier, log rank test, and life table were used to describe the data. The Cox proportional hazard regression model was used for analysis.

Results

The findings of this study revealed that the overall occurrence of cardiac arrest among critically ill ICU patients was 27% (95% CI: 23, 32). The incidence density rate of cardiac arrest among intensive care unit patients was 19.6 per 1000 person-days of observation. In a multivariable analysis, patients with chronic kidney disease, oxygen saturation <90%, delirium, intubation, and patients admitted to the ICU with cardiovascular disease were found to be independent predictors of cardiac arrest in the Intensive Care Unit.

Conclusion

The incidence density rate of cardiac arrest among intensive care unit patients was high. This study also revealed that chronic kidney disease, delirium, intubation, oxygen saturation level below 90% and patients admitted with cardiovascular disease were independent predictors of the occurrence of cardiac arrest among intensive care unit patients. Finally, we recommend that clinician pays attention to those identified as preventable risk factors for early interventions to improve the recovery process of patients in the ICU.

Intramuscular and abdominal fat measured by computed tomography and mortality of hemodialysis patients

BACKGROUND

In hemodialysis patients, high body mass index is associated with low mortality while abdominal obesity relates to increased mortality. We aimed to investigate the association between muscle mass, intramuscular fat and abdominal fat measured by abdominal computed tomography (CT), and mortality in this patients population.

METHODS

This two-center retrospective cohort study included hemodialysis patients who underwent abdominal CT between January 2013 and December 2018. Skeletal muscle mass index (SMI), muscle radiation attenuation (MRA) as an index of intramuscular fat, and visceral fat to subcutaneous fat ratio (VSR) were calculated using CT images at the third lumbar vertebral level. Multivariate Cox proportional hazards model was used to determine the independent predictors of all-cause, cardiovascular and non-cardiovascular mortalities.

RESULTS

The study included 344 patients (median age 71.0 years; female 33.7%), among whom 145 died during a median follow-up of 4.9 years-46 and 99 from cardiovascular and non-cardiovascular causes, respectively. Lower MRA [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.58-0.87, P = .001] and higher VSR (HR 1.17, 95% CI 1.01-1.37, P = .04) were independently associated with higher all-cause mortality but not with lower SMI (HR 0.87, 95% CI 0.68-1.11, P = .26). Lower MRA (HR 0.51, 95% CI 0.35-0.73, P < .001) and higher VSR (HR 1.29, 95% CI 1.09-1.54, P = .003) were also associated with cardiovascular and non-cardiovascular mortality, respectively.

CONCLUSIONS

Intramuscular fat and abdominal fat as measured using abdominal CT in hemodialysis patients are stronger independent predictors of mortality than muscle mass.

Arginine-methylated c-Myc affects mitochondrial mitophagy in mouse acute kidney injury via Slc25a24

The transcription factor methylated c-Myc heterodimerizes with MAX to modulate gene expression, and plays an important role in energy metabolism in kidney injury but the exact mechanism remains unclear. Mitochondrial solute transporter Slc25a24 imports ATP into mitochondria and is central to energy metabolism. Gene Expression Omnibus data analysis reveals Slc25a24 and c-Myc are consistently upregulated in all the acute kidney injury (AKI) cells. Pearson correlation analysis also shows that Slc25a24 and c-Myc are strongly correlated (⍴ > 0.9). Mutant arginine methylated c-Myc (R299A and R346A) reduced its combination with MAX when compared with the wild type of c-Myc. On the other hand, the Slc25a24 levels were also correspondingly reduced, which induced the downregulation of ATP production. The results promoted reactive oxygen species (ROS) production and mitophagy generation. The study revealed that the c-Myc overexpression manifested the most pronounced mitochondrial DNA depletion. Additionally, the varied levels of mitochondrial proteins like TIM23, TOM20, and PINK1 in each group, particularly the elevated levels of PINK1 in AKI model groups and lower levels of TIM23 and TOM20 in the c-Myc overexpression group, suggest potential disruptions in mitochondrial dynamics and homeostasis, indicating enhanced mitophagy or mitochondrial loss. Therefore, arginine-methylated c-Myc affects mouse kidney injury by regulating mitochondrial ATP and ROS, and mitophagy via Slc25a24.

Impact of recombinant human brain natriuretic peptide on emergency dialysis and prognosis in end-stage renal disease patients with type 4 cardiorenal syndrome

Recombinant human brain natriuretic peptide (rhBNP) effects on type 4 cardiorenal syndrome (CRS) and adverse events such as heart failure rehospitalization and all-cause mortality have not been assessed in large-scale research. This study evaluated the impact of rhBNP on emergency dialysis and prognosis in end-stage renal disease (ESRD) patients with type 4 CRS, and the risk factors of emergency dialysis. This retrospective cohort study included patients with type 4 CRS and ESRD admitted for decompensated heart failure between January 2016 and December 2021. Patients were divided into the rhBNP and non-rhBNP cohorts, according to whether they were prescribed rhBNP. The primary outcomes were emergency dialysis at first admission and cardiovascular events within a month after discharge. A total of 77 patients were included in the rhBNP cohort (49 males and 28 females, median age 67) and 79 in the non-rhBNP cohort (47 males and 32 females, median age 68). After adjusting for age, residual renal function, and primary diseases, Cox regression analysis showed that rhBNP was associated with emergency dialysis (HR = 0.633, 95% CI 0.420-0.953) and cardiovascular events (HR = 0.410, 95% CI 0.159-0.958). In addition, multivariate logistic regression analysis showed that estimated glomerular filtration rate (eGFR) (OR = 0.782, 95% CI 0.667-0.917, P = 0.002) and procalcitonin (PCT) levels (OR = 1.788, 95% CI 1.193-2.680, P = 0.005) at the first visit were independent risk factors for emergency dialysis while using rhBNP was a protective factor for emergency dialysis (OR = 0.195, 95% CI 0.084-0.451, P < 0.001). This study suggests that RhBNP can improve cardiac function and reduce the occurrence of emergency dialysis and cardiovascular events in ESRD patients with type 4 CRS.

The Association of Ejection Fraction With Hospital-Associated Cardiac Arrest and Heart Failure Hospitalization Differs According to Baseline Estimated GFR

Introduction

Chronic kidney disease (CKD) and left ventricular (LV) dysfunction are risk factors for cardiovascular events. We explore whether the association of LV ejection fraction (LVEF) with cardiac arrest, heart failure hospitalization, and all-cause mortality differs across stages of kidney impairment.

Methods

We performed an observational cohort study of 19,032 patients from 2004 to 2014 with estimated glomerular filtration rate (eGFR) ≤90 ml/min per 1.73 m2 and without end-stage kidney disease (ESKD). Cox regression models, incorporating an interaction term for eGFR and LVEF, were fit and adjusted for relevant covariates.

Results

Mean age of the patients was 67 ± 14 years, and 51% were male. The mean eGFR was 64 ± 19 ml/min per 1.73 m2 and LVEF was 54 ± 13%. Over a median follow-up of 3.0 (0.7-6.0) years there were 504 cardiac arrests, 4181 heart failure hospitalizations, and 6989 deaths. The association of LVEF with cardiac arrest and heart failure hospitalization differed according to continuous eGFR (P-interaction <0.01 for both outcomes). The association of LVEF with cardiac arrest in the lowest quartile was attenuated (adjusted hazard ration [aHR] per 5% higher LVEF 0.92; 95% confidence interval [CI] 0.88-0.96) compared to the highest eGFR quartile (aHR per 5% higher LVEF 0.85; 95% CI 0.78-0.91). The association of LVEF with heart failure hospitalization was similarly attenuated in the lowest eGFR quartile. There was no effect modification of LVEF by continuous eGFR for all-cause mortality (P-interaction 0.26).

Conclusion

Among non-ESKD patients with eGFR ≤90 ml/min per 1.73 m2, the association of LVEF with cardiac arrest and heart failure hospitalization is attenuated at lower levels of kidney function. Further research is required to elucidate what factors beyond LVEF drive these observations.

In-hospital outcomes of PCI in patients who have ESRD vs non-ESRD patients, a retrospective study involving a National Inpatient Sample (NIS) database

BACKGROUND

Cardiovascular disease is the leading cause of death for patients with end-stage renal disease (ESRD). ESRD is known to affect a large portion of the American population. Previous data for patients undergoing percutaneous coronary intervention (PCI) in the setting of ESRD for Acute Coronary Syndrome (ACS) and non-ACS etiologies have shown to have an increase in in-hospital mortality, and prolonged hospitalization among other complications.

METHODS

The national inpatient sample (NIS) was used to identify patients who underwent PCI between the years 2016-2019. Patients were then grouped into those with ESRD on renal replacement therapy (RRT). Logistic regression models were employed to assess the primary outcome of in-hospital mortality, while linear regression models were utilized to evaluate secondary outcomes, including hospitalization cost and length of stay.

RESULTS

A total of 21,366 unweighted observations were initially included, consisting of 50 % ESRD patients and 50 % randomly selected patients without ESRD who underwent PCI. These observations were weighted to represent a national estimate of 106,830 patients. The mean age of the study population was 65 years, and 63 % of the patients were male. The ESRD group had a greater representation of minority groups compared to the control group. The in-hospital mortality rate was significantly higher in the ESRD group compared to the control group, with an odds ratio of 1.803 (95 % CI: 1.502 to 2.164; p-value of 0.0002). Additionally, the ESRD group had significantly higher healthcare costs and longer length of stay, with a mean difference of $47,618 (95 % CI: $42,701 to $52,534, p-value <0.0001) and 2.933 days (95 % CI, 2.729 to 3.138 days, p-value <0.0001), respectively.

CONCLUSION

In-hospital mortality, cost, and length of stay for patients undergoing PCI were found to be significantly greater in the ESRD group.

OSTEOPROTEGERIN AS AN EARLY SIGN OF CHRONIC KIDNEY DISEASE-MINERAL AND BONE DISORDER

Chronic kidney disease (CKD) is among the most significant health problems, with the associated cardiovascular disease and bone metabolism disorders being the leading cause of morbidity and mortality in these patients. The aim of the study was to determine markers of bone turnover in patient sera (phosphates, calcium, alkaline phosphatase, parathyroid hormone and osteoprotegerin (OPG)) in all stages of kidney failure including kidney transplant recipients. We also wanted to determine whether dialysis vintage affects recovery of bone markers one year after transplantation. There were 164 study patients, whereas 30 healthy individuals served as a control group. Serum OPG progressively increased with decline of the glomerular filtration rate. The highest OPG concentration was recorded in dialysis group. We observed a statistically significant OPG increase in stage 2 CKD. In kidney transplant group, there was positive correlation between OPG and dialysis vintage. We also found that serum OPG was lower in patients treated with dialysis for less than 4 years prior to transplantation. We confirmed that CKD-mineral and bone disorder began in stage 3 CKD with parathyroid hormone and OPG elevation, and a statistically significant OPG increase in stage 2 CKD might be an early sign of CKD-mineral and bone disorder. Dialysis vintage longer than 4 years is associated with more significant disturbances in mineral and bone metabolism.

Diagnosing Arterial Stiffness in Pregnancy and Its Implications in the Cardio-Renal-Metabolic Chain

Cardio-renal and metabolic modifications during gestation are crucial determinants of foetal and maternal health in the short and long term. The cardio-renal metabolic syndrome is a vicious circle that starts in the presence of risk factors such as obesity, hypertension, diabetes, kidney disease and ageing, all predisposing to a status dominated by increased arterial stiffness and alteration of the vascular wall, which eventually damages the target organs, such as the heart and kidneys. The literature is scarce regarding cardio-renal metabolic syndrome in pregnancy cohorts. The present paper exposes the current state of the art and emphasises the most important findings of this entity, particularly in pregnant women. The early assessment of arterial function can lead to proper and individualised measures for women predisposed to hypertension, pre-eclampsia, eclampsia, and diabetes mellitus. This review focuses on available information regarding the assessment of arterial function during gestation, possible cut-off values, the possible predictive role for future events and modalities to reverse or control its dysfunction, a fact of crucial importance with excellent outcomes at meagre costs.

Nationwide study of mortality and sudden cardiac death in young persons diagnosed with chronic kidney disease

AIMS

The aim of this study was to compare short- and long-term risk of sudden cardiac death (SCD) among persons aged 18-49 years with and without chronic kidney disease (CKD).

METHODS AND RESULTS

Using Danish nationwide health registries, all persons aged 18-49 years diagnosed with earlier stages of CKD or chronic kidney failure from 1 July 1995 through 2009 were identified. Non-exposed subjects matched on sex and birth-year were identified. All SCD in the Danish population aged 18-49 years in 2000-2009 have previously been identified using information from the Danish nationwide health registries, death certificates, and autopsy reports. In total, 9308 incident cases of earlier stage CKD and 1233 incident cases of chronic kidney failure were included. Among patients with earlier stage CKD, the absolute risk of SCD 1, 5, and 10 years after diagnosis was 0.14%, 0.37%, and 0.68%, respectively. Compared with age- and sex-matched subjects the corresponding relative risk (RR) was 20.3 [95% confidence interval (CI) 8.4-48.8], 7.1 (95% CI 4.2-12.0), and 6.1 (95% CI 3.8-9.7), respectively. Among patients with chronic kidney failure, the absolute 1-, 5-, and 10-year risk of SCD was 0.17%, 0.56%, and 2.07%, respectively. The corresponding RR was 12.5 (95% CI 1.4-111.6), 7.9 (95% CI 2.3-27.0), and 10.1 (95% CI 4.5-22.6).

CONCLUSION

Persons with earlier stage CKD and chronic kidney failure had increased risk of SCD compared with the background population with a 6- to 20-fold increased risk of SCD. These findings underline the importance of early cardiovascular risk monitoring and assessment in persons with CKD.

Kidney function and the risk of sudden cardiac death in the general population

Background

Chronic kidney disease increases sudden cardiac death (SCD) risk, but the association between kidney function and SCD in a general population is largely unknown. Therefore, we investigated the association between kidney function and SCD in a general middle-aged and elderly population.

Methods

We included individuals aged ≥45 years from a prospective population-based cohort study. The association between kidney function assessments [estimated glomerular filtration rate based on serum creatinine (eGFRcreat), cystatin C (eGFRcys) or both (eGFRcreat-cys)] and SCD was investigated using Cox proportional-hazards and joint models. Absolute 10-year risks were computed using competing risk analyses. Mediation analyses were performed using a four-way decomposition method.

Results

We included 9687 participants (median follow-up 8.9 years; mean age 65.3 years; 56.7% women; 243 SCD cases). Lower eGFRcys and eGFRcreat-cys were associated with increased SCD risk [hazard ratio (HR) 1.23, 95% confidence interval (CI) 1.12–1.34 and HR 1.17, 95% CI 1.06–1.29, per 10 mL/min/1.73 m² eGFR decrease]. A significant trend (P = 0.001) across eGFRcys categories was found, with an HR of 2.11 (95% CI 1.19–3.74) for eGFRcys <60 compared with eGFRcys >90 mL/min/1.73 m². Comparing eGFRcys of 90 to 60 mL/min/1.73 m², absolute 10-year risk increased from 1.0% to 2.5%. Identified subgroups at increased risk included older participants and participants with atrial fibrillation. The associations were not mediated by coronary heart disease, hypertension or diabetes.

Conclusions

Reduced kidney function is associated with increased SCD risk in the general population, especially with eGFRcys. eGFRcys could be added to prediction models and screening programmes for SCD prevention.

Mild renal insufficiency and attributable risk of adverse In-hospital outcomes in patients with Acute Coronary Syndrome from the improving care for Cardiovascular Disease in China (CCC) project

Background

Renal insufficiency (RI) is a frequent comorbidity among patients with acute coronary syndrome (ACS). We aimed to evaluate the attributable risk associated with mild RI for the in-hospital outcomes in patients with ACS.

Methods

The Improving Care for Cardiovascular Disease in China-ACS (CCC-ACS) Project was a collaborative study of the American Heart Association and the Chinese Society of Cardiology. A total of 92,509 inpatients with a discharge diagnosis of ACS were included. The attributable risk was calculated to investigate the effect of mild RI (eGFR 60-89 ml / min · 1.73 m²) on major adverse cardiovascular events (MACEs) during hospitalization.

Results

The average age of these ACS patients was 63 years, and 73.9% were men. The proportion of patients with mild RI was 36.17%. After adjusting for other possible risk factors, mild RI was still an independent risk factor for MACEs in ACS patients. In the ACS patients, the attributable risk of eGFR 60-89ml/min·1.73m² to MACEs was 7.78%, 4.69% of eGFR 45-59 ml/min·1.73m², 4.46% of eGFR 30-44 ml/min·1.73m², and 3.36% of eGFR<30 ml/min·1.73m².

Conclusion

Compared with moderate to severe RI, mild RI has higher attributable risk to MACEs during hospitalization in Chinese ACS population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02663-4.

The fundamental role of stress echo in evaluating coronary artery disease in specific patient populations

Stress echocardiography (SE) was initially used for assessing patients with known or suspected coronary heart disease by detecting and evaluating myocardial ischemia and viability. The implementation of SE has gradually been extended to several cardiovascular diseases beyond coronary artery disease, and SE protocols have been modified and adapted for the detection of coronary artery disease (CAD) or other cardiovascular diseases in specific patient populations. This review attempts to summarize current data concerning SE implementation and clinical value in these specific and diverse populations: patients with an intramural course of a coronary artery - known as a myocardial bridge, chronic severe or end-stage hepatic disease, chronic severe or end-stage kidney disease, cardiac allograft vasculopathy, patients scheduled for solid-organ transplantation and other intermediate and high-risk surgery and, finally, patients treated with anticancer drugs or radiotherapy.

Ventricular arrhythmias in mouse models of diabetic kidney disease

Chronic kidney disease (CKD) affects more than 20 million people in the US, and it is associated with a significantly increased risk of sudden cardiac death (SCD). Despite the significance, the mechanistic relationship between SCD and CKD is not clear and there are few effective therapies. Using optical mapping techniques, we tested the hypothesis that mouse models of progressive diabetic kidney disease (DKD) exhibit enhanced ventricular arrhythmia incidence and underlying arrhythmia substrates. Compared to wild-type mice, both Lepr^db/db eNOS^−/− (2KO) and high fat diet plus low dose streptozotocin (HFD + STZ) mouse models of DKD experienced sudden death and greater arrhythmia inducibility, which was more common with isoproterenol than programmed electrical stimulation. 2KO mice demonstrated slowed conduction velocity, prolonged action potential duration (APD), and myocardial fibrosis; both 2KO and HFD + STZ mice exhibited arrhythmias and calcium dysregulation with isoproterenol challenge. Finally, circulating concentrations of the uremic toxin asymmetric dimethylarginine (ADMA) were elevated in 2KO mice. Incubation of human cardiac myocytes with ADMA prolonged APD, as also observed in 2KO mice hearts ex vivo. The present study elucidates an arrhythmia-associated mechanism of sudden death associated with DKD, which may lead to more effective treatments in the vulnerable DKD patient population.

Sex-specific differences and long-term outcome of patients with coronary artery disease and chronic kidney disease: the Coronary Artery Disease and Renal Failure (CAD-REF) Registry

BACKGROUND

Cardiovascular morbidity and mortality are closely linked to chronic kidney disease (CKD). Sex-specific long-term outcome data of patients with coronary artery disease (CAD) and CKD are scarce.

METHODS

In the prospective observational multicenter Coronary Artery Disease and REnal Failure (CAD-REF) Registry, 773 (23.1%) women and 2,579 (76.9%) men with angiographically documented CAD and different stages of CKD were consecutively enrolled and followed for up to 8 years. Long-term outcome was evaluated using survival analysis and multivariable Cox-regression models.

RESULTS

At enrollment, women were significantly older than men, and suffered from more comorbidities like CKD, hypertension, diabetes mellitus, and multivessel coronary disease. Regarding long-term mortality, no sex-specific differences were observed (Kaplan-Meier survival estimates: 69% in women vs. 69% in men, plog-rank = 0.7). Survival rates decreased from 89% for patients without CKD at enrollment to 72% for patients with CKD stages 1-2 at enrollment and 49% for patients with CKD stages 3-5 at enrollment (plog-rank < 0.001). Cox-regression analysis revealed that sex or multivessel coronary disease were no independent predictors of long-term mortality, while age, CKD stages 3-5, albumin/creatinine ratio, diabetes, valvular heart disease, peripheral artery disease, and left-ventricular ejection fraction were predictors of long-term mortality.

CONCLUSIONS

Sex differences in CAD patients mainly exist in the cardiovascular risk profile and the extent of CAD. Long-term mortality was not depended on sex or multivessel disease. More attention should be given to treatment of comorbidities such as CKD and peripheral artery disease being independent predictors of death. Clinical Trail Registration ClinicalTrials.gov Identifier: NCT00679419.

High Oxalate Concentrations Correlate with Increased Risk for Sudden Cardiac Death in Dialysis Patients

BACKGROUND

The clinical significance of accumulating toxic terminal metabolites such as oxalate in patients with kidney failure is not well understood.

METHODS

To evaluate serum oxalate concentrations and risk of all-cause mortality and cardiovascular events in a cohort of patients with kidney failure requiring chronic dialysis, we performed a post-hoc analysis of the randomized German Diabetes Dialysis (4D) Study; this study included 1255 European patients on hemodialysis with diabetes followed-up for a median of 4 years. The results obtained via Cox proportional hazards models were confirmed by competing risk regression and restricted cubic spline modeling in the 4D Study cohort and validated in a separate cohort of 104 US patients on dialysis after a median follow-up of 2.5 years.

RESULTS

A total of 1108 patients had baseline oxalate measurements, with a median oxalate concentration of 42.4 µM. During follow-up, 548 patients died, including 139 (25.4%) from sudden cardiac death. A total of 413 patients reached the primary composite cardiovascular end point (cardiac death, nonfatal myocardial infarction, and fatal or nonfatal stroke). Patients in the highest oxalate quartile (≥59.7 µM) had a 40% increased risk for cardiovascular events (adjusted hazard ratio [aHR], 1.40; 95% confidence interval [95% CI], 1.08 to 1.81) and a 62% increased risk of sudden cardiac death (aHR, 1.62; 95% CI, 1.03 to 2.56), compared with those in the lowest quartile (≤29.6 µM). The associations remained when accounting for competing risks and with oxalate as a continuous variable.

CONCLUSIONS

Elevated serum oxalate is a novel risk factor for cardiovascular events and sudden cardiac death in patients on dialysis. Further studies are warranted to test whether oxalate-lowering strategies improve cardiovascular mortality in patients on dialysis.

Effects of Intradialytic Exercise on Dialytic Parameters, Health-Related Quality of Life, and Depression Status in Hemodialysis Patients: A Randomized Controlled Trial

Exercise is fundamentally important in managing chronic diseases and improving health-related quality of life (HRQL). However, whether intradialytic exercise is safe through assessment of changes in dialytic parameters and has a positive impact on HRQL and depression status of hemodialysis patients requires further research with diverse racial and cultural populations to identify. This study aimed to evaluate the effects of intradialytic exercise on dialytic parameters, HRQL, and depression status in hemodialysis patients. A randomized controlled trial was conducted at a medical center in Northern Taiwan. Sixty-four hemodialysis patients were recruited using stratified random sampling. Participants were randomized into an experimental group (EG, n = 32) or a control group (CG, n = 32). The EG received a 12-week intradialytic exercise program while the CG maintained their usual lifestyles. Dialytic parameters, HRQL, and depression status were collected at baseline and at 12 weeks. The results indicated no differences in the dialytic parameters from the baseline between both groups. However, the EG had increased HRQL (ß = 22.6, p < 0.001) and reduced depression status (ß = −7.5, p = 0.02) at 12 weeks compared to the CG. Therefore, a 12-week intradialytic exercise regime is safe and effective in improving HRQL and reducing depression status for hemodialysis patients.

Intermedin1‑47 inhibits high phosphate‑induced vascular smooth muscle cell calcification by regulating Wnt/β‑catenin signaling

Vascular calcification is a major risk factor for cardiovascular disease and accounts for a large proportion of deaths from cardiovascular disease in patients with chronic kidney disease. The high incidence, rapid progression and irreversibility of vascular smooth muscle cell (VSMC) calcification in patients has attracted attention. In the present study, the effect of intermedin1‑47 (IMD1‑47), an important isoform of intermedin, was investigated on the calcification of rat cardiovascular VSMCs induced by high phosphate (HP). To stimulate osteoblast‑like differentiation and calcification in rat VSMCs, 10 mM β‑sodium glycerophosphate was used. The VSMCs were then treated with three doses of IMD1‑47 and the effects of IMD1‑47 on VSMC calcification, on the expression of osteogenic markers [osteoprotegerin, Runt‑related transcription factor 2 (Runx2) and osteopontin (OPN)] and on alkaline phosphatase (ALP) activity were assessed. HP treatment significantly enhanced the cellular calcium content of VSMCs, the expression of osteogenic markers, and ALP activity, while IMD1‑47 significantly reversed these effects in a dose‑dependent manner. The protein expression levels of Wnt1, Wnt3a and active β‑catenin were determined and it was found that IMD1‑47 significantly inhibited their expression. Following β‑catenin silencing, the protein expression levels Runx2 and OPN were increased compared with the IMD1‑47 treatment alone, indicating a role for the Wnt/β‑catenin pathway in the effects of IMD1‑47 on osteogenic markers. The present study suggested that IMD1‑47 inhibited HP‑induced VSMC calcification by regulating the Wnt/β‑catenin signaling pathway.

Heart Rate Variability and Long Chain n-3 Polyunsaturated Fatty Acids in Chronic Kidney Disease Patients on Haemodialysis: A Cross-Sectional Pilot Study

Low heart rate variability (HRV) is independently associated with increased risk of sudden cardiac death (SCD) and all cardiac death in haemodialysis patients. Long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may exert anti-arrhythmic effects. This study aimed to investigate relationships between dialysis, sleep and 24 h HRV and LC n-3 PUFA status in patients who have recently commenced haemodialysis. A cross-sectional study was conducted in adults aged 40–80 with chronic kidney disease (CKD) stage 5 (n = 45, mean age 58, SD 9, 20 females and 25 males, 39% with type 2 diabetes). Pre-dialysis blood samples were taken to measure erythrocyte and plasma fatty acid composition (wt % fatty acids). Mean erythrocyte omega-3 index was not associated with HRV following adjustment for age, BMI and use of β-blocker medication. Higher ratios of erythrocyte eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) were associated with lower 24 h vagally-mediated beat-to-beat HRV parameters. Higher plasma EPA and docosapentaenoic acid (DPAn-3) were also associated with lower sleep-time and 24 h beat-to-beat variability. In contrast, higher plasma EPA was significantly related to higher overall and longer phase components of 24 h HRV. Further investigation is required to investigate whether patients commencing haemodialysis may have compromised conversion of EPA to DHA, which may impair vagally-mediated regulation of cardiac autonomic function, increasing risk of SCD.

Uremic Toxins and Their Relation with Oxidative Stress Induced in Patients with CKD

The presence of toxins is believed to be a major factor in the development of uremia in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Uremic toxins have been divided into 3 groups: small substances dissolved in water, medium molecules: peptides and low molecular weight proteins, and protein-bound toxins. One of the earliest known toxins is urea, the concentration of which was considered negligible in CKD patients. However, subsequent studies have shown that it can lead to increased production of reactive oxygen species (ROS), and induce insulin resistance in vitro and in vivo, as well as cause carbamylation of proteins, peptides, and amino acids. Other uremic toxins and their participation in the damage caused by oxidative stress to biological material are also presented. Macromolecules and molecules modified as a result of carbamylation, oxidative stress, and their adducts with uremic toxins, may lead to cardiovascular diseases, and increased risk of mortality in patients with CKD.

Near-sudden unexpected death in a patient with epilepsy undergoing hemodialysis: a case report

Sudden unexpected death in epilepsy (SUDEP) has been defined as a sudden/unexpected, witnessed/unwitnessed, nontraumatic, and nondrowning death in epileptic patients with/without seizure evidence and documented status epilepticus. Identified as the leading cause of epilepsy-related deaths, SUDEP cases are highly unrecognized and underreported due to diagnostic difficulty. We report a case of a successfully revived hemodialysis patient who developed cardiopulmonary arrest after a witnessed convulsive seizure. Electroencephalogram revealed epileptic abnormalities. Therefore, this case could be seizure-induced cardiopulmonary arrest and near-SUDEP. Hence, the possibility of SUDEP should be considered even in hemodialysis patients having conventional coronary risk factors for sudden cardiac death.

Effect of Renal Dysfunction on Risk of Sudden Cardiac Death in Patients With Hypertrophic Cardiomyopathy

Renal dysfunction is a known risk of sudden cardiac death in patients with ischemic heart disease. However, the association between renal dysfunction and sudden death in hypertrophic cardiomyopathy (HC) patients remains unknown. This study investigated the significance of an impaired renal function for the sudden death risk in a cohort of patients with HC. We included 450 patients with HC (mean age 52.9 years, 65.1% men). The estimated glomerular filtration rate (eGFR) was evaluated at the time of the initial evaluation. Renal dysfunction was defined as an eGFR <60 ml/min/1.73 m². Renal dysfunction was found in 171 patients (38.0%) at the time of enrollment. Over a median (IQR) follow-up period of 8.8 (5.0 to 12.5) years, 56 patients (12.4%) experienced the combined end point of sudden death or potentially lethal arrhythmic events, including 20 with sudden death (4.4%), 11 resuscitated after a cardiac arrest, and 25 with appropriate implantable defibrillator shocks. Patients with renal dysfunction were at a significantly higher risk of sudden death (Log-rank p = 0.034) and the combined end point (Log-rank p <0.001) than patients without renal dysfunction. After adjusting for the highly imbalanced baseline variables, the eGFR remained as an independent correlate of the combined end point (adjusted hazard ratio: 1.24 per 10 ml/min decline in the eGFR; 95% confidence interval 1.04 to 1.47; p = 0.013). In conclusion, an impaired renal function may be associated with an incremental risk of sudden death or potentially lethal arrhythmic events in patients with HC.

A Personalized Approach to Chronic Kidney Disease and Cardiovascular Disease: JACC Review Topic of the Week

Cardiovascular disease is the most common cause of death in patients with end-stage renal disease (ESRD). The initiation of dialysis for treatment of ESRD exacerbates chronic electrolyte and hemodynamic perturbations. Rapid large shifts in effective intravascular volume and electrolyte concentrations ultimately lead to subendocardial ischemia, increased left ventricular wall mass, and diastolic dysfunction, and can precipitate serious arrhythmias through a complex pathophysiological process. These factors, unique to advanced kidney disease and its treatment, increase the overall incidence of acute coronary syndrome and sudden cardiac death. To date, risk prediction models largely fail to incorporate the observed cardiovascular mortality in the CKD population; however, multimodality imaging may provide an additional prognostication and risk stratification. This comprehensive review discusses the cardiovascular risks associated with hemodialysis, and explores the pathophysiology and the novel utilization of multimodality imaging in CKD to promote a personalized approach for these patients with implications for future research.

Asystole episodes and bradycardia in patients with end-stage renal disease

BACKGROUND

Knowledge of arrhythmias in patients with end-stage renal disease (ESRD) is mainly based on ambulatory electrocardiography (ECG) studies and observations during haemodialysis. We used insertable cardiac monitors to define the prevalence of arrhythmias, focusing on bradyarrhythmias, in ESRD patients treated with several dialysis modes including home therapies. Moreover, we assessed whether these arrhythmias were detected in baseline or ambulatory ECG recordings.

METHODS

Seventy-one patients with a subcutaneously insertable cardiac monitor were followed for up to three years. Asystole (≥4.0 secs) and bradycardia (heart rate <30 bpm for ≥4 beats) episodes, ventricular tachyarrhythmias and atrial fibrillation were collected and verified visually. A baseline ECG and a 24-48-hour ambulatory ECG were recorded at recruitment and once a year thereafter.

RESULTS

At recruitment, forty-four patients were treated in in-center haemodialysis, 12 in home haemodialysis and 15 in peritoneal dialysis. During a median follow-up of 34.4 months, 18 (25.4%) patients had either an asystolic or a bradycardic episode. The median length of each patient's longest asystole was 6.6 seconds and that of a bradycardia 13.5 seconds. Ventricular tachyarrhythmias were detected in 16 (23%) patients, and atrial fibrillation in 34 (51%) patients. In-center haemodialysis and type II diabetes were significantly more frequent among those with bradyarrhythmias whereas no bradyarrhythmias were found in home haemodialysis. No bradyarrhythmias were evident in baseline or ambulatory ECG recordings.

CONCLUSIONS

Remarkably many patients with ESRD had bradycardia or asystolic episodes, but these arrhythmias were not detected by baseline or ambulatory ECG.

Management of acute intradialytic cardiovascular complications: Updated overview (Review)

An increasing number of patients require renal replacement therapy through dialysis and renal transplantation. Chronic kidney disease (CKD) affects a large percentage of the world's population and has evolved into a major public health concern. Diabetes mellitus, high blood pressure and a family history of kidney failure are all major risk factors for CKD. Patients in advanced stages of CKD have varying degrees of cardiovascular damage. Comorbidities of these patients, include, on the one hand, hypertension, hyperlipidemia, hyperglycemia, hyperuricemia and, on the other hand, the presence of mineral-bone disorders associated with CKD and chronic inflammation, which contribute to cardiovascular involvement. Acute complications occur quite frequently during dialysis. Among these, the most important are cardiovascular complications, which influence the morbidity and mortality rates of this group of patients. Chronic hemodialysis patients manifest acute cardiovascular complications such as intradialytic hypotension, intradialytic hypertension, arrhythmias, acute coronary syndromes and sudden death. Thus, proper management is extremely important.

Developing a Standardized and Reusable Method to Link Distributed Health Plan Databases to the National Death Index: Methods Development Study Protocol

BACKGROUND

Certain medications may increase the risk of death or death from specific causes (eg, sudden cardiac death), but these risks may not be identified in premarket randomized trials. Having the capacity to examine death in postmarket safety surveillance activities is important to the US Food and Drug Administration's (FDA) mission to protect public health. Distributed networks of electronic health plan databases used by the FDA to conduct multicenter research or medical product safety surveillance studies often do not systematically include death or cause-of-death information.

OBJECTIVE

This study aims to develop reusable, generalizable methods for linking multiple health plan databases with the Centers for Disease Control and Prevention's National Death Index Plus (NDI+) data.

METHODS

We will develop efficient administrative workflows to facilitate multicenter institutional review board (IRB) review and approval within a distributed network of 6 health plans. The study will create a distributed NDI+ linkage process that avoids sharing of identifiable patient information between health plans or with a central coordinating center. We will develop standardized criteria for selecting and retaining NDI+ matches and methods for harmonizing linked information across multiple health plans. We will test our processes within a use case comprising users and nonusers of antiarrhythmic medications.

RESULTS

We will use the linked health plan and NDI+ data sets to estimate the incidences and incidence rates of mortality and specific causes of death within the study use case and compare the results with reported estimates. These comparisons provide an opportunity to assess the performance of the developed NDI+ linkage approach and lessons for future studies requiring NDI+ linkage in distributed database settings. This study is approved by the IRB at Harvard Pilgrim Health Care in Boston, MA. Results will be presented to the FDA at academic conferences and published in peer-reviewed journals.

CONCLUSIONS

This study will develop and test a reusable distributed NDI+ linkage approach with the goal of providing tested NDI+ linkage methods for use in future studies within distributed data networks. Having standardized and reusable methods for systematically obtaining death and cause-of-death information from NDI+ would enhance the FDA's ability to assess mortality-related safety questions in the postmarket, real-world setting.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/21811.

Contribution of Predictive and Prognostic Biomarkers to Clinical Research on Chronic Kidney Disease

Chronic kidney disease (CKD), defined as the presence of albuminuria and/or reduction in estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2, is considered a growing public health problem, with its prevalence and incidence having almost doubled in the past three decades. The implementation of novel biomarkers in clinical practice is crucial, since it could allow earlier diagnosis and lead to an improvement in CKD outcomes. Nevertheless, a clear guidance on how to develop biomarkers in the setting of CKD is not yet available. The aim of this review is to report the framework for implementing biomarkers in observational and intervention studies. Biomarkers are classified as either prognostic or predictive; the first type is used to identify the likelihood of a patient to develop an endpoint regardless of treatment, whereas the second type is used to determine whether the patient is likely to benefit from a specific treatment. Many single assays and complex biomarkers were shown to improve the prediction of cardiovascular and kidney outcomes in CKD patients on top of the traditional risk factors. Biomarkers were also shown to improve clinical trial designs. Understanding the correct ways to validate and implement novel biomarkers in CKD will help to mitigate the global burden of CKD and to improve the individual prognosis of these high-risk patients.

Implantable Cardioverter Defibrillators and Chronic Kidney Disease

Use of implantable cardioverter defibrillators (ICDs) is the treatment of choice for heart failure patients with ejection fraction <35% to prevent sudden cardiac death. Whether this benefit remains among patients with chronic kidney disease (CKD) or end stage renal disease (ESRD) is yet to be elucidated. We conducted a systematic review of studies in PubMed that have investigated the use of ICDs among patients with CKD or ESRD. From the 470 studies identified, we selected 42 for the current review. Patients with CKD/ESRD were more likely to get antitachycardia pacing or shocks and had higher cardiac and/or all-cause mortality compared to patients without CKD/ESRD. These associations had an inverse dose-response effect with worse outcomes with decreasing kidney function. In conclusion, use of ICDs in CKD/ESRD is associated with increased antitachycardia pacing/shocks and mortality suggesting that their routine use in this patient population may be associated with more adverse outcomes than benefits.

Coronary Artery Disease in patients with End-Stage Kidney Disease; Current perspective and gaps of knowledge

Coronary artery disease (CAD) is very common in dialysis patients. One third have preexisting CAD and another one third have significant occult disease at the time of starting dialysis. Symptoms are often absent or are atypical, emphasizing the need for vigorous screening, specifically in patients awaiting transplant. The lesions tend to be heavily calcified, diffuse, and involve multiple vessels, consequently, percutaneous coronary interventions are more complicated to perform, and are less successful in achieving and maintaining short- and long-term patency. Dialysis patients have been excluded from the randomized controlled trials on which the current standards for managing CAD have been established. Due to differences in pathobiology and risks and benefits, it is uncertain that the results of these clinical trials extrapolate to patients with advanced chronic kidney disease (CKD). Here we review the data from observational studies and identify special considerations concerning the diagnosis and management of CAD in dialysis patients, including the use of noninvasive functional testing vs anatomical testing, the management of acute coronary syndromes and of stable coronary artery disease, the role for percutaneous revascularization vs coronary artery bypass grafting, and of platelet inhibitor therapy after coronary stenting. We review the preliminary results of the recently published ISCHEMIA-CKD trial, the only trial to date to involve large numbers of dialysis patients. This is the first of, hopefully, many trials in the pipeline that will examine therapies for CAD specifically in patients with advanced CKD, a growing population that is at particularly high risk for poor outcomes.

Targeting Vascular Calcification in Chronic Kidney Disease

Cardiovascular (CV) disease remains an important cause of morbidity and mortality for patients with chronic kidney disease (CKD). Although clustering of traditional risk factors with CKD is well recognized, kidney-specific mechanisms are believed to drive the disproportionate burden of CV disease. One perturbation that is frequently observed at high rates in patients with CKD is vascular calcification, which may be a central mediator for an array of CV sequelae. This review summarizes the pathophysiological bases of intimal and medial vascular calcification in CKD, current strategies for diagnosis and management, and posits vascular calcification as a risk marker and therapeutic target.

A Joint Evaluation of Neurohormone Vasopressin-Neurophysin II-Copeptin and Aortic Arch Calcification on Mortality Risks in Hemodialysis Patients

Objective: Systemic hypoperfusion is intricately involved in neurohormone secretion, vascular calcification (VC) related impaired vasodilation, and luminal stenosis. We aimed to conduct a joint evaluation of vasopressin-neurophysin II-copeptin peptide (VP) and advanced aortic arch calcification (AAC) on all-cause and cardiovascular (CV) mortality in maintenance hemodialysis (MHD) patients. Methods: Unadjusted and adjusted hazard ratios (aHRs) of mortality risks were analyzed for different groups of VP and AAC in 167 MHD patients. The modification effect between higher VP and advanced AAC on mortality risk was examined using an interaction product term. Results: Interactions between VP and AAC with respect to all-cause and CV mortality were statistically significant. In multivariable analysis, higher VP predicted all-cause and CV mortality [aHR: 2.2 (95% confidence interval (CI): 1.1-4.5)] and 2.6 (95% CI: 1.1-4.6), respectively. Advanced AAC was associated with incremental risks of all-cause and CV mortality [aHR: 2.1 (95% CI: 1.1-4.0)and 2.5 (95% CI: 1.0-4.3), respectively]. Patients with combined higher VP (>101.5 ng/mL) and advanced AAC were at the greatest risk of all-cause and CV mortality [aHR: 4.7 (95% CI: 1.2-16.2)and 4.9 (95% CI: 1.1-18.9), respectively]. Conclusion: Combined VP and advanced AAC predict not only all-cause but also CV death in MHD patients, and a joint evaluation is more comprehensive than single marker. In light of hypoperfusion and ischemic events in vital organs, VP and AAC could act as more robust dual marker for prognostic assessment.

Sympathetic Activation in Hypertensive Chronic Kidney Disease - A Stimulus for Cardiac Arrhythmias and Sudden Cardiac Death?

Studies have revealed a robust and independent correlation between chronic kidney disease (CKD) and cardiovascular (CV) events, including death, heart failure, and myocardial infarction. Recent clinical trials extend this range of adverse CV events, including malignant ventricular arrhythmias and sudden cardiac death (SCD). Moreover, other studies point out that cardiac structural and electrophysiological changes are a common occurrence in this population. These processes are likely contributors to the heightened hazard of arrhythmias in CKD population and may be useful indicators to detect patients who are at a higher SCD risk. Sympathetic overactivity is associated with increased CV risk, specifically in the population with CKD, and it is a central feature of the hypertensive state, occurring early in its clinical course. Sympathetic hyperactivity is already evident at the earliest clinical stage of CKD and is directly related to the progression of renal failure, being most pronounced in those with end-stage renal disease. Sympathetic efferent and afferent neural activity in kidney failure is a crucial facilitator for the perpetuation and evolvement of the disease. Here, we will revisit the role of the feedback loop of the sympathetic neural cycle in the context of CKD and how it may aggravate several of the risk factors responsible for causing SCD. Targeting the overactive sympathetic nervous system therapeutically, either pharmacologically or with newly available device-based approaches, may prove to be a pivotal intervention to curb the substantial burden of cardiac arrhythmias and SCD in the high-risk population of patients with CKD.

Risk Factors of In-Hospital Lethal Arrhythmia Following Acute Myocardial Infarction in Patients Undergoing Primary Percutaneous Coronary Intervention - Insight From the J-MINUET Study

Background: Lethal arrhythmias including ventricular tachycardia and fibrillation (VT/VF) are common complications of acute myocardial infarction (AMI). Predictors of in-hospital VT/VF after AMI, however, have not been thoroughly investigated. In this study, we sought to elucidate the predictors of in-hospital VT/VF events after AMI in the Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET). Methods and Results: In-hospital VT/VF was defined as a hemodynamically unstable VT or VF in the first week of hospitalization, on which the patients were classified as the VT/VF group. Of the patients in the J-MINUET study, 3,175 were finally enrolled in this study. A total of 114 patients had VT/VF. On multivariate logistic analysis, maximum creatine kinase >3,000 IU/L (adjusted OR, 1.67; 95% CI: 1.085-2.572; P=0.02), Killip class III or IV (adjusted OR, 8.93; 95% CI: 5.668-14.082; P<0.0001), initial Thrombolysis in Myocardial Infarction (TIMI) flow grade 0 or 1 (adjusted OR, 1.67; 95% CI: 1.035-2.709; P=0.03), and concomitant chronic kidney disease (CKD; adjusted OR, 1.80; 95% CI: 1.105-2.938; P=0.02) were identified as independent predictors for in-hospital VT/VF. Conclusions: From the J-MINUET study, extensive myocardial damage, cardiogenic shock, lower grade initial TIMI flow on coronary angiography, and concomitant CKD were independent predictors of in-hospital VT/VF after AMI.

End stage renal disease modifies the effect of targeted temperature management after out-of-hospital cardiac arrest

INTRODUCTION

Kidney function can affect the permeability of the blood-brain barrier; thus, end-stage renal disease (ESRD) may alter the effects of targeted temperature management (TTM) on the neurological outcomes of out-of-hospital cardiac arrest (OHCA) patients. We aimed to investigate whether the interaction effect of TTM on outcomes after OHCA was observed among patients with and without ESRD.

METHODS

Adult OHCA patients with presumed cardiac etiology who attained sustained return of spontaneous circulation from 2013 to 2017 were included using nationwide OHCA registry. The main exposure variable was TTM. The primary endpoint was survival with good neurological recovery. Multivariable logistic regression analysis was performed after adjustment for potential confounders. To compare the effect of ESRD on TTM, an interaction term (TTM × ESRD) was added to the model.

RESULTS

A total of 21,250 patients were included in the analysis; 2693 (12.7%) patients underwent TTM. ESRD was observed in 128 (4.8%) in the TTM group and 767 (4.1%) in the no-TTM group. The TTM group showed better outcomes than the no-TTM group (32.4% vs. 17.2%, p < 0.01). The adjusted odds ratio of TTM for good neurological recovery in the entire study group was 1.15 (95% CI, 1.03-1.29). In the interaction model, the adjusted odds ratio of TTM for good neurological recovery was 0.47 (95% CI, 0.23-0.98) in the ESRD group vs. 1.54 (95% CI, 1.00-2.39) in the no-ESRD group.

CONCLUSIONS

The interaction effect between ESRD and TTM on neurologic outcome was positive in adult OHCA initial survivors with presumed cardiac etiology.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

Fluctuations in plasma potassium in patients on dialysis

Plasma potassium concentration is maintained in a narrow range to avoid deleterious electrophysiologic consequences of both abnormally low and high levels. This is achieved by redundant physiologic mechanisms, with the kidneys playing a central role in maintaining both short-term plasma potassium stability and long-term total body potassium balance. In patients with end-stage renal disease, the lack of kidney function reduces the body’s ability to maintain normal physiologic potassium balance. Routine thrice-weekly dialysis therapy achieves long-term total body potassium mass balance, but the intermittent nature of dialytic therapy can result in wide fluctuations in plasma potassium concentration and consequently contribute to an increased risk of arrhythmogenicity. Various dialytic and nondialytic interventions can reduce the magnitude of these fluctuations, but the impact of such interventions on clinical outcomes remains unclear.

Prevalence and Significance of Renal Dysfunction Among Emergency Department Observation Patients With Chest Pain

OBJECTIVES

Previous studies have demonstrated increased risk of acute coronary syndrome among patients with chest pain and renal dysfunction. The objective of this study was to investigate the impact of renal dysfunction on cardiac outcomes in patients with chest pain in an emergency department observation unit (EDOU).

METHODS

We conducted a 5-year prospective evaluation of patients evaluated in the EDOU for chest pain. We collected baseline information and data from the emergency department visit, EDOU stay, inpatient admission, and the 30-day period after presentation to the emergency department. We calculated glomerular filtration rate (GFR) using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. We stratified patients as having mild (GFR 60-89 mL/min per 1.73 m) or at least moderate (GFR <60) renal dysfunction. We evaluated the rate of major adverse cardiac events (MACE: myocardial infarction, stent, coronary artery bypass graft, and death).

RESULTS

Of 1067 enrolled EDOU patients, the majority had at least mild renal dysfunction: 39% [95% confidence interval (95% CI): 36.1%-42%] had a GFR between 60 and 89, and 16% (95% CI: 14%-18.4%) had a GFR <60. MACE rates increased with decreasing GFR: 3.3% (95% CI: 2.1%-5.3%) for GFR ≥90, 7.3% (95% CI: 5.2%-10.2%) for GFR 60-89, and 9.1% (95% CI: 5.7%-14.3%) for GFR <60 (P = 0.005). In multivariate analysis, patients with at least mild renal dysfunction (GFR < 90) were at greater risk of MACE (P = 0.028).

CONCLUSIONS

We noted a high prevalence of renal dysfunction among EDOU patients evaluated for chest pain. Even those with mild renal dysfunction demonstrated an increased risk of MACE. Clinicians may wish to consider renal dysfunction in selecting appropriate patients for EDOU placement.

The axis of local cardiac endogenous Klotho-TGF-β1-Wnt signaling mediates cardiac fibrosis in human

BACKGROUND

Cardiovascular fibrosis is a major contributor to cardiovascular disease, the primary cause of death in patients with chronic kidney disease (CKD). We previously reported expression of endogenous Klotho in human arteries, and that CKD is a state of Klotho deficiency, resulting in vascular calcification, but myocardial expression of Klotho is poorly understood. This study aimed to further clarify endogenous Klotho's functional roles in cardiac fibrosis in patients with underlying CKD.

METHODS AND RESULTS

Human atrial appendage specimens were collected during cardiac surgery from individuals with or without CKD. Cardiac fibrosis was quantified using trichrome staining. For endogenous Klotho functional studies, primary human cardiomyocytes (HCMs) were treated with uremic serum from CKD patients or recombinant human TGF-β1. The effects of endogenous Klotho in HCMs were studied using Klotho-siRNA and Klotho-plasmid transfection. Both gene and protein expression of endogenous Klotho are found in human heart, but decreased Klotho expression is clearly associated with the degree of cardiac fibrosis in CKD patients. Moreover, we show that endogenous Klotho is expressed by HCMs and cardiac fibroblasts (HCFs) but that HCM expression is suppressed by uremic serum or TGF-β1. Klotho knockdown or overexpression aggravates or mitigates TGF-β1-induced fibrosis and canonical Wnt signaling in HCMs, respectively. Furthermore, co-culture of HCMs with HCFs increases TGF-β1-induced fibrogenic proteins in HCFs, but overexpression of endogenous Klotho in HCMs mitigates this effect, suggesting functional crosstalk between HCMs and HCFs.

CONCLUSIONS

Our data from analysis of human hearts as well as functional in vitro studies strongly suggests that the loss of cardiac endogenous Klotho in CKD patients, specifically in cardiomyocytes, facilitates intensified TGF-β1 signaling which enables more vigorous cardiac fibrosis through upregulated Wnt signaling. Upregulation of endogenous Klotho inhibits pathogenic Wnt/β-catenin signaling and may offer a novel strategy for prevention and treatment of cardiac fibrosis in CKD patients.

The Incidence and Associated Factors of Sudden Death in Patients on Hemodialysis: 10-Year Outcome of the Q-Cohort Study

Aim: The incidence of sudden death and its risk factors in patients on hemodialysis remain unclear. This study aimed to clarify the incidence of sudden death and its risk factors in Japanese patients on hemodialysis.

Methods: A total of 3505 patients on hemodialysis aged ≥ 18 years were followed for 10 years. Multivariate-adjusted hazard ratio (HR) with 95% confidence interval (95% CI) of each risk factor of sudden death were calculated using a Cox proportional hazards model.

Results: During the 10-year follow-up, 1735 patients died, including 227 (13%) sudden deaths. The incidence rate of sudden death was 9.13 per 1000 person-years. In multivariable-adjusted Cox analysis, male sex (HR 1.67; 95% CI 1.20–2.33), age (HR 1.44; 95% CI 1.26–1.65 per 10-year higher), the presence of diabetes (HR 2.45; 95% CI 1.82–3.29), history of cardiovascular disease (HR 1.85; 95% CI 1.38–2.46), cardiothoracic ratio (HR 1.21; 95% CI 1.07–1.39 per 5% higher), serum C-reactive protein (HR 1.11; 95% CI 1.03–1.20 per 1-mg/dL higher), and serum phosphate (HR 1.15; 95% CI 1.03–1.30 per 1-mg/dL higher) were independent predictors of sudden death. A subgroup analysis stratified by sex or age showed that lower serum corrected calcium levels, not using vitamin D receptor activators in women, and a shorter dialysis session length in men or older people (≥ 65 years) increased the risk for sudden death.

Conclusions: This study clarified the incidence of sudden death and its specific predictors in Japanese patients on hemodialysis.

Serum potassium level on hospital arrival and survival after out-of-hospital cardiac arrest: The CRITICAL study in Osaka, Japan

BACKGROUND

Little is known about the association between serum potassium level on hospital arrival and neurological outcome after out-of-hospital cardiac arrest (OHCA). We investigated whether the serum potassium level on hospital arrival had prognostic indications for patients with OHCA.

METHODS

This prospective, multicenter observational study conducted in Osaka, Japan (CRITICAL study) enrolled consecutive patients with OHCA transported to 14 participating institutions from 2012 to 2016. We included adult patients aged ⩾18 years with OHCA of cardiac origin who achieved return of spontaneous circulation and whose serum potassium level on hospital arrival was available. Based on the serum potassium level, patients were divided into four quartiles: Q1 (K ⩽3.8 mEq/L), Q2 (3.8< K⩽4.5 mEq/L), Q3 (4.5< K⩽5.6 mEq/L) and Q4 (K >5.6 mEq/L). The primary outcome was one-month survival with favorable neurological outcome, defined as cerebral performance category scale 1 or 2.

RESULTS

A total of 9822 patients were registered, and 1516 of these were eligible for analyses. The highest proportion of favorable neurological outcome was 44.8% (189/422) in Q1 group, followed by 30.3% (103/340), 11.7% (44/375) and 4.5% (17/379) in the Q2, Q3 and Q4 groups, respectively (p<0.001). In the multivariable analysis, the proportion of favorable neurological outcome decreased as the serum potassium level increased (p<0.001).

CONCLUSIONS

High serum potassium level was significantly and dose-dependently associated with poor neurological outcome. Serum potassium on hospital arrival would be one of the effective prognostic indications for OHCA achieving return of spontaneous circulation.

Rates of Cardiac Rhythm Abnormalities in Patients with CKD and Diabetes

BACKGROUND AND OBJECTIVES

Cardiac arrhythmias increase mortality and morbidity in CKD. We evaluated the rates of subclinical arrhythmias in a population with type 2 diabetes and patients with moderate to severe CKD who were not on dialysis.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

This is a prospective observational study, using continuous ambulatory cardiac monitors to determine the rate of atrial and ventricular arrhythmias, as well as conduction abnormalities in this group.

RESULTS

A total of 38 patients (34% women), with mean eGFR of 38±13 ml/min per 1.73 m², underwent ambulatory cardiac monitoring for 11.2±3.9 days. The overall mean rate of any cardiac arrhythmia was 88.8 (95% confidence interval [95% CI], 27.1 to 184.6) episodes per person-year (PY). A history of cardiovascular disease was associated with a higher rate of detected arrhythmia (rate ratio, 5.87; 95% CI, 1.37 to 25.21; P<0.001). The most common arrhythmia was atrial fibrillation, which was observed in two participants with known atrial fibrillation and was a new diagnosis in four patients (11%), none of whom experienced symptoms. Overall, atrial fibrillation episodes occurred at a rate of 37.6 (95% CI, 2.4 to 112.3) per PY. Conduction abnormalities were found in eight patients (21%), a rate of 26.5 (95% CI, 4.2 to 65.5) per PY. Rates of ventricular arrhythmias were low (14.5 per PY; 95% CI, 4.3 to 32.0) and driven by premature ventricular contractions.

CONCLUSIONS

Cardiac rhythm abnormalities are common in patients with diabetes with moderate to severe CKD not requiring dialysis. Rates of atrial fibrillation are high and episodes are asymptomatic. Future studies are needed to determine the role of screening and upstream therapy of cardiac arrhythmias in this group.

The Association of Kidney Function and Albuminuria With the Risk and Outcomes of Syncope: A Population-Based Cohort Study

BACKGROUND

The risks and subsequent outcomes of syncope among seniors with chronic kidney disease (CKD) are unclear.

METHODS

We conducted a population-based retrospective cohort study of 272,146 patients ≥ 66 years old, in Ontario, Canada, from April 1, 2006, to March 31, 2016. Using administrative health care databases, we examined the association of estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (ACR) with incident syncope and the association of incident syncope with the composite outcome of myocardial infarction, stroke, and death by levels of eGFR/ACR, using adjusted Cox proportional hazards models.

RESULTS

A total of 15,074 incident syncopal events occurred during the study period. The adjusted risk for syncope was higher with a lower eGFR and higher ACR in a stepwise manner (eGFR 60 to < 90: HR 1.17 [1.09-1.26] vs eGFR < 30: HR 1.67 (1.50-1.87) with eGFR ≥ 90 referent; ACR > 30: HR 1.15 [1.07-1.24] with ACR < 3 referent). Among the 12,710 patients with a first syncope event and 1 year of follow-up, the adjusted risk for the composite outcome was higher with a lower eGFR and higher ACR in a stepwise manner (eGFR 60 to < 90: HR 1.05 [0.90-1.22] vs eGFR < 30: HR 1.62 [1.34-1.96] with eGFR ≥ 90 referent; ACR > 30: HR 1.77 [1.60-1.96], ACR < 3 referent).

CONCLUSIONS

A lower eGFR and higher ACR are associated with a higher risk of a hospital encounter for syncope and of related complications among persons of advanced age.

Working Toward an Improved Understanding of Chronic Cardiorenal Syndrome Type 4

Chronic diseases of the heart and of the kidneys commonly coexist in individuals. Certainly combined and persistent heart and kidney failure can arise from a common pathologic insult, for example, as a consequence of poorly controlled hypertension or of severe diffuse arterial disease. However, strong evidence is emerging to suggest that cross talk exists between the heart and the kidney. Independent processes are set in motion when kidney function is chronically diminished, and these processes can have distinct adverse effects on the heart. The complex chronic heart condition that results from chronic kidney disease (CKD) has been termed cardiorenal syndrome type 4. This review will include an updated description of the cardiac morphology in patients who have CKD, an overview of the most likely CKD-sourced culprits for these cardiac changes, and the potential therapeutic strategies to limit cardiac complications in patients who have CKD.

Cardiotoxicity of Uremic Toxins: A Driver of Cardiorenal Syndrome

Cardiovascular disease (CVD) is highly prevalent in the setting of chronic kidney disease (CKD). Such coexistence of CVD and CKD—the so-called “cardiorenal or renocardiac syndrome”—contributes to exponentially increased risk of cardiovascular (CV) mortality. Uremic cardiomyopathy is a characteristic cardiac pathology commonly found in CKD. CKD patients are also predisposed to heart rhythm disorders especially atrial fibrillation. Traditional CV risk factors as well as known CKD-associated CV risk factors such as anemia are insufficient to explain CV complications in the CKD population. Accumulation of uremic retention solutes is a hallmark of impaired renal excretory function. Many of them have been considered inert solutes until their biological toxicity is unraveled and they become accepted as “uremic toxins”. Direct cardiotoxicity of uremic toxins has been increasingly demonstrated in recent years. This review offers a mechanistic insight into the pathological cardiac remodeling and dysfunction contributed by uremic toxins with a main focus on fibroblastic growth factor-23, an emerging toxin playing a central role in the chronic kidney disease–mineral bone disorder, and the two most investigated non-dialyzable protein-bound uremic toxins, indoxyl sulfate and p-cresyl sulfate. Potential therapeutic strategies that could address these toxins and their relevant mediated pathways since pre-dialysis stages are also discussed.